Asia Pacific Foundation for Infectious Diseases (APFID), Seoul 135-710, Korea.
Diagn Microbiol Infect Dis. 2011 Apr;69(4):370-5. doi: 10.1016/j.diagmicrobio.2010.10.019.
We investigated changes of serotypes in Streptococcus pneumoniae and the characteristics of serotypes 6A and 6B in Korean hospitals after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). PCV7 serotypes decreased significantly from 66.8% in 1996-2001 to 41.3% in 2008-2009 (P<0.001). However, serotype 6B did not decrease during these 2 periods (5.7% to 6.4%). Non-PCV7 serotypes that increased significantly were 3 (3.6% to 9.1%), 6A (3.1% to 8.5%), 13/28 (0 to 3.7%), 15 (2.2% to 6.7%), 16.36.37 (0 to 1.2%), 19A (1.2% to 9.7%), and 23A (0 to 1.5%). Multilocus sequence typing indicated that 9 STs were identified among 36 isolates of serotype 6A and 19 among 35 isolates of serotype 6B. No STs were found both in the 2 serotypes. The increase in serotype 6A was associated mainly with ST81, a Spain-23F clone genotype. The association of serotype 6A and ST81 is unique to Korea. Clones of serotype 6B isolates changed between the 2 periods. ST282, the main clone of serotype 6B in the PCV7 period, was found only in Korea. Our study demonstrates changing characteristics of pneumococcal serotypes 6A and 6B isolates in Korea and suggests selective evolution of certain clones in the era of PCV7 vaccination.
我们调查了肺炎链球菌血清型的变化，以及在引入 7 价肺炎球菌结合疫苗（PCV7）后韩国医院 6A 和 6B 血清型的特点。PCV7 血清型从 1996-2001 年的 66.8%显著下降到 2008-2009 年的 41.3%（P<0.001）。然而，这两个时期 6B 血清型并没有下降（5.7%至 6.4%）。显著增加的非 PCV7 血清型为 3（3.6%至 9.1%）、6A（3.1%至 8.5%）、13/28（0 至 3.7%）、15（2.2%至 6.7%）、16.36.37（0 至 1.2%）、19A（1.2%至 9.7%）和 23A（0 至 1.5%）。多位点序列分型表明，在 36 株 6A 血清型分离株和 35 株 6B 血清型分离株中鉴定出 9 种 ST 型。两种血清型均未发现 ST 型。6A 血清型的增加主要与 ST81 有关，ST81 是西班牙 23F 克隆基因型。6A 血清型和 ST81 的关联是韩国特有的。两个时期 6B 血清型分离株的克隆发生了变化。在 PCV7 时期，6B 血清型的主要克隆 ST282 仅在韩国发现。我们的研究表明，韩国肺炎链球菌 6A 和 6B 分离株的血清型特征发生了变化，并提示在 PCV7 疫苗接种时代，某些克隆发生了选择性进化。
